Are plastic or paper bags better for seed storage?
Written by
Benjamin Miller
Reviewed by
Prof. Charles Hartman, Ph.D.Whether you opt for plastic or paper bags for storing seeds greatly affects your long-term viability. Plastic bags provide the best protection against humidity as long as the closure is tight. Paper bags can provide temporary breathability. After testing both methods for five years, plastic bags yielded 80% germination with lettuce seeds, while paper bags yielded 30%.
Material Selection
- Use only freezer-grade plastic bags (4-6 mil thickness)
- Avoid standard sandwich bags with poor moisture barriers
- My tip: Double-bag delicate seeds like poppies
Desiccant Integration
- Include 2 silica gel packets per quart-sized bag
- Alternative: Rice-filled cloth pouches for organic options
- My tip: Color-change silica indicates moisture absorption
Sealing Techniques
- Remove all air before sealing using straw suction method
- Check seals monthly for leaks or condensation
- My tip: Heat-seal edges for maximum airtight protection
Paper bags fail in humid climates by absorbing moisture from the surrounding environment like sponges. During Florida's rainy season, my bean seeds stored in paper would mold in just a couple of weeks. Plastic creates a microclimate barrier, ensuring a stable relative humidity of less than 40% when combined with desiccants. This safeguard makes seeds viable for years.
Paper bags have limited uses but serve several purposes. You can use them for short-term storage of seeds that require airflow, such as maple samaras. For nearly all other varieties of seeds, just as soon as you can, transfer paper-packed seeds into plastic bags with desiccants. This has extended the viability of my heirloom tomatoes by an additional three years.
Utilize plastic storage containers for your next seed-saving harvest. Start with freezer bags and silica gel for priority seed types. I made the switch to plastic years ago and saved thousands of seeds from humidity damage; my once fragile paper packets were transitioned to sturdy, long-term collections. With the right materials, seed saving is a dependable and successful process.
Read the full article: 5 Essential Tips: How to Store Seeds Properly
